Miniature pushbutton dry reed switch

ABSTRACT

A precision-type snap switch embodying a reed-type switch providing sealed contacts, and a printed circuit board supporting the reed-type switch and conductively connecting selectively the sealed contacts to exposed switch terminals.

United States Patent lnventor Richard E. Bell Princeton, Ind. 15,668 Mar. 2, 1970 Oct. 12, I97 1 American Machine & Foundry Company AppL No. Filed Patented Assignee MINIATURE PUSI'IBU I'ION DRY REED SWITCH 3,448,419 6/1969 Myatt Reierences Cited UNITED STATES PATENTS Primary Examiner-Semard A. Gilheany Assistant Examiner-R. N. Envall, Jr. Artarneys-George W. Price and Charles J. Worth ABSTRACT: A precision-type snap switch embodying a reedtype' switch providing sealed contacts, and a printed circuit board supporting the reed-type switch and conductively connecting selectively the sealed contacts to exposed switch terminais.

I! II PATENTEDBEI 12m FIG)! INVENTOR RICHARD E.

MINIATURE rusrrsurron DRY REED swrrcn This invention relates generally to precision-type snap switches and more particularly to miniature size switches of this type having sealed contacts. I

As precision-type snap switches were made progressively smaller, assembly became more and more difficult Tl-ie with contacts sealed against contamination.

Another object of the present invention is to provide the foregoing snap switch with improved conductive connecting and support means for the contacts.

Still another object of the present invention is to provide the foregoing snap switch in which engagement between the switch actuator and the movable contact is eliminated.

And another object of the present invention is to provide the foregoing snap switch which can be assembled with facility.

The foregoing and other objects and advantages will appear more fully hereinafter from a consideration of the detailed description which follows, taken together with the accompanying drawings wherein several embodiments of the invention are illustrated by way of example. it is to be expressly understood, however, that the drawings are for illustration purposes only and are not to be construed as defining the limits of the invention.

FIG. I is a side view of a precision-type snap switch, in accordance with the present invention, with the cover removed to expose a printed circuit board providing support and conductive connections for the switch contacts.

FIG. 2 is a view similar toFlG. l with a portionof the printed circuit board broken away.

FIGS.3 and 4 are sectional views taken on lines 3-3 and 4-4, respectively, FIG. 1.

FIG. Sis a side view of another form of precision-type snap.

switch, in accordance with the present invention, with the cover and printed circuit board removed thereon.

FIG. 6 is a sectional view taken on line 6-6 ofFiO. 5.

Referring now to the drawings and to particularly FIGS. 1 to 4, a switch S in accordance with the present invention is provided with the usual miniature precisiomtype snap awitch enclosure means forrned by acase l0 and a cover 12 both of dielectric material which are connected together in the usual manner by suitable fastener means such as rivets 13. The case 10 is hollow to define a switch chamber ll, and has terminal means provided by a common (C.) terminal 14, a normally closed (N.C.) terminal 16 and a normally open (N.C.) terminal 18 which eitend from the defined chamber 11 through the case 10 and are supported thereby. The ends of the terminals or terminal members 14, 16 and- 18 in the switch chamber II are provided with lugs or tab portions l5, l7 and 19, respectively, which extend laterally toward the cover 12.

The switch S is provided with printed circuit (P.C.) board means which is retained between the case 10 and cover 12 by the fasteners 13. The printed circuit board means is formed in the usual manner by a board 20 of dielectric material with three conductors 21, 22 and 23 each electrically isolated from the others on one side of the board; preferably, but not limited to the side adjacent the cover 12 as shown in the drawings.

With the PC. board means positioned in this manner each end of the conductors 21, 22 and 23 is provided with an opening which extends through the board 20. y

The lugs or tab portions l5, l7 and 19, of the respective terminal members l4, l6 and 18, extend through the appropriate openings in the board 20 and are soldered or otherwise suitably connected to conductors 21, 22 and 23, respectively. The switch S has sealed contact means provided by a reed switch 25 disposed in the switch chamber II. The reed switch 25 is provided with A (C.) contact 27 and (N.C.) contact 28 terminal 18. The electrical connection of the contacts 27, 28

and 29 also supports the reed switch 25 in the switch chamber 11. Thus, the PC. board means forms an electrical connector and a support for the sealed contacts (reed switch 25) of the switch 8.

The actuating means of the switch S is provided by a push-' button 30 of dielectric material which extends through the case 10 into the chamber ll and mounts a permanent magnet 31. Preferably, the pushbutton 30 is hollow and the magnet 31 fits therein as a core. A leaf spring 32 in the chamber 11 is mountedat one end and at its other end engages the inner end of the pushbutton 30 to provide a spring bias or force urging the pushbutton to its outermost or.unoperated position.

As the pushbutton 30 is depressed against the bias of the spring 32, the magnet 31 is moved axially toward the reed switch 25. The (C.) contact 27, which normally engages the (N.C.) contact 28, is magnetically responsive to the field of the magnet 31, when moved toward the reed switch 25, and moves out of engagement with the (N.C.) contact 28 and into engagement with the (N.C.) contact 29. Upon release of the pushbutton 30, the magnet 31 is moved away from the reed switch 25 and the (C.) contact 27 thereof returns to its original position. While the reed switch 25 is a singlepoleldouble-throw switch, it could be normally open (N .0.) or a normally closed (N.C.) make/break switch. in such an instance, an appropriate conductor of the P.C. board means and the terminal member connected thereto could be omitted from the switch 8. As shown in FIG. 2, the magnet 31 could be removed from the pushbutton 30 and alternatively be mounted on the leaf spring 32, as indicated at 33.

Referring now to FIGS. 4 and 5, another switch S2, in accordance with the present invention, is shown which differs from the switch 5 only with respect to its housing and actuating means. The switch S2 is provided with the same cover 12; fasteners 13; terminal means l4, l6 and 18; RC. board means 20, 21, 22 and 23; and reed switch 25 as the switch S of H65. 1 to 4. The switch S2 is provided with a hollow case 40 which defines a switch chamber 41 corresponding to the case 10 and chamber ll, respectively, of Switch S. The chamber 41 has an inwardly extending flange or wall portion 42 intermediate its ends and, the case 40 is provided with a peripheral flange or pushbutton 45 is provided with an inner operating or cam portion 46 with an opening 47 therethrough providing a cam surface. A magnet or magnet assembly 50 is provided with a cam follower 51 which extends into the opening 47 and engages the cam surface. The magnet or magnet assembly 50 is rotatably mounted by a shaft or torsion spring 52 supported at its ends in the flange 42 and an end wall of the chamber 41. if a common shaft 52 is used, suitable spring means is provided to return the magnet assembly 50 to its original position when the pushbutton 45 is released. Axial movement of the pushbutton 45, through its cam portion 46 and the cam follower 5!, causes the magnet means 50 to rotate toward and away from the reed switch 25 for switch operation.

Although several embodiments of the invention have been illustrated and described in detail, it is to be expressly understood that the invention is not limited thereto. Various changes may be made in the design and arrangement of the parts without departing from the spirit and scope of the invenn hollow case 'd'efininga switch chamberopen 4 day said printed circuit board means;

meansretained between said case and tion as the menu new be understood by those skilled in are I art. a f F I lclaimz;

- terminal' means extending from the chamber outwar zlly I through said case and beingconnected to and supported ;-ma'gnetieally responsive contact means thc'cl'lim r; .i

actuating means supportedbysaid'case and including a per-' ,"Irna'nent magnet means movable toward and away from s'aidsealed contact means (orswitch operation; and I V a said circuit board means conductively connecting'selective a ly said contact and terminal means, andsupporting said contactmcansin the switch chamber.

2. Ap ret :i sion:-t:ype snap switch in accordance withclaim l,

and e I r saidlsealedcontact means comprising a reedswitch with a 'pluralityof contacts'each with'an exposed portion;

Quid @rminal means compn'sing a plurality oi' electrically conductive terrninal'rnembers;

said printed c edit I I 'dielectric materialand a pluralityo'i' electrical conductors disposed in I and means comprising I board {of and.

' said actuating means including an axially movable push but tonextending fromsaid chamber outwardly throu'gh said case. and a spring means disposed in said chamber; and

said spring means engaging and biasing said 'pushbutton outwardly to a normal unactuated position.

I 5. A precision-type snap switchin-accordance with' claim t,

and

' said pushbutton being hollow; and 1 I said permanent magnet means being disposed in said push i button.

- adjacent saidcoverdefining a recess therein; and

V vsaid board dielectiic material being disposed in said recess on one side ot' said board electrically isolatedfrom one I ganothe'nand's I r I I i each of said conductorsielectricallylconnecting a-difl'erent i onjegof said contacts and tennin'als to each other. '7

3. precision-type snapswitch in accordancewith claim 2,

said peripheral flangeextending from its side 7 adjacent said cover defining a recess therein; and

board of dielectric material being disposed in said recess. Y 1

7 g n1 v 40 I 4 A precision-type snap switch in accordance with claim 2 i i 7-. A precision-type snap switch in accordance withclairn 4, V

saidfipring being aileaf -typ'e spring mounted at one endjand I i Q engaging the inner end or said pushbutton at its other end;]'. land said permanent magnet means being mounted on said I leaf-type spring.

' 8, A precision-type snap switch accordance with claim 7,

fsaid case having a peripheral flange extending from its side} adjacent s'aidcover defining a recess thereim and' said ,board of dielectric material being disposed recess. I

'n said 9'. A precision-typesnap switchjn accordance with claim 4 :1

and 1 said,permanentmagnet1being rotatably mo unted?inxthe} 5 a chamber; and cam means causing said in responseto axial'movernent of said pushbirtto'n,

10. A precision-type snap switch in accordance with claim i .9,and i said case having vjacent side cover defining a recess therein; and

saidof dielectric material being disposediin said recess.

1 6. A precision-type snap switch in accordancewith claim 5," ..and I t said case having a'peripheral flange extending from its side permanent magnet means n rotate l 1 a peripheral m c mill ram ada 

1. A precision-type snap switch comprising: a hollow case defining a switch chamber open on one side thereof; a cover connected to said case closing the open side of the chamber; printed circuit board means retained between said case and said cover; terminal means extending from the chamber outwardly through said case and being connected to and supported by said printed circuit board means; sealed magnetically responsive contact means disposed in the chamber; actuating means supported by said case and including a permanent magnet means movable toward and away from said sealed contact means for switch operation; and said circuit board means conductively connecting selectively said contact and terminal means, and supporting said contact means in the switch chamber.
 2. A precision-type snap switch in accordance with claim l, and said sealed contact means comprising a reed switch with a plurality of contacts each with an exposed portion; said terminal means comprising a plurality of electrically conductive terminal members; said printed circuit board means comprising a board of dielectric material and a plurality of electrical conductors on one side of said board electrically isolated from one another; and each of said conductors electrically connecting a different one of said contacts and terminals to each other.
 3. A precision-type snap switch in accordance with claim 2, and said case having a peripheral flange extending from its side adjacent said cover defining a recess therein; and said board of dielectric material being disposed in said recess.
 4. A precision-type snap switch in accordance with claim 2, and said actuating means including an axially movable pushbutton extending from said chamber outwardly through said case, and a spring means disposed in said chamber; and said spring means engaging and biasing said pushbutton outwardly to a normal unactuated position.
 5. A precision-type snap switch in accordance with claim 4, and said pushbutton being hollow; and said permanent magnet means being disposed in said pushbutton.
 6. A precision-type snap switch in accordance with claim 5, and said case having a peripheral flange extending from its side adjacent said cover defining a recess therein; and said board dielectric material being disposed in said recess.
 7. A precision-type snap switch in accordance with claim 4, and said spring being a leaf-type spring mounted at one end and engaging the inner end of said pushbutton at its other end; and said permanent magnet means being mounted on said leaf-type spring.
 8. A precision-type snap switch in accordance with claim 7, and said case having a peripheral flange extending from its side adjacent said cover defining a recess therein; and said board of dielectric material being disposed in saId recess.
 9. A precision-type snap switch in accordance with claim 4, and said permanent magnet being rotatably mounted in the chamber; and cam means causing said permanent magnet means to rotate in response to axial movement of said pushbutton.
 10. A precision-type snap switch in accordance with claim 9, and said case having a peripheral flange extending from its adjacent side cover defining a recess therein; and said board of dielectric material being disposed in said recess. 